A current detection protection system based on triode switching characteristics

Abstract

The utility model discloses a current detection protection system based on triode switching characteristic relates to electronic circuit technical field, including main control module, switch module, current detection module, alarm module and power module, the input of main control module is electric connection with the output of current detection module, the input of current detection module electric connection has switch module, power module and main control module electric connection are used for carrying out power supply. The utility model discloses through triode switching characteristic, need not additional amplifier or ADC, realizes the detection to the current, and response speed is fast, has improved current monitoring efficiency, can complete protection action in microsecond level, and cost is low, and circuit design is simple, and the application in low -power consumption equipment is convenient, can adjust protection threshold value flexibly, has improved the applicability of system.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, specifically to a current detection and protection system based on the switching characteristics of a transistor. Background Technology

[0002] Current detection and protection circuits are indispensable and critical components in electronic equipment and power systems. When a short circuit or excessive load occurs in a circuit, the current will rise sharply, potentially exceeding the rated current withstand value of equipment (such as chips, motors, and capacitors). Current detection circuits monitor current changes in real time. Once a preset threshold is exceeded, the protection circuit will quickly trigger actions (such as cutting off power or current limiting) to prevent permanent damage to components due to overheating or breakdown. Current is one of the core parameters of circuit operation; its changes directly reflect whether the system is functioning normally. When an abnormal current occurs in a local circuit, the protection circuit can quickly isolate the fault area, preventing the fault from spreading to the entire system and reducing the risk of overall system failure.

[0003] Currently, most common current protection circuits on the market employ operational amplifiers, dedicated detection chips, or complex control circuits. However, these solutions suffer from problems such as circuit complexity, high power consumption, slow response speed, and high cost. These factors combined not only increase the difficulty of research and development and production but also make subsequent maintenance and repair extremely challenging, resulting in high costs throughout the entire lifecycle and hindering widespread market adoption. Utility Model Content

[0004] To address the aforementioned technical problems, a current detection and protection system based on transistor switching characteristics is provided. This technical solution overcomes the limitations of the current protection circuits mentioned in the background, which often employ operational amplifiers, dedicated detection chips, or complex control circuits. However, these solutions suffer from circuit complexity, high power consumption, slow response speed, and high cost. These factors combined not only increase the difficulty of research and development and production but also make subsequent maintenance and repair extremely challenging, resulting in high costs throughout the entire lifecycle and hindering widespread market adoption.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A current detection and protection system based on transistor switching characteristics includes a main control module, a switch module, a current detection module, an alarm module, and a power supply module. The input terminal of the main control module is electrically connected to the output terminal of the current detection module, the input terminal of the current detection module is electrically connected to the switch module, and the power supply module is electrically connected to the main control module for supplying power. The current detection module is used to detect current signals and transmit them to the main control module; The alarm module is electrically connected to the output terminal of the main control module and is used to issue an alarm signal when current is detected.

[0006] Preferably, the main control module integrates a U5 chip, pin 9 of the U5 chip is electrically connected to a 5V voltage input, a capacitor C9 is connected in parallel to pin 9 of the U5 chip and grounded, pin 7 of the U5 chip is grounded, and a resistor R29 is connected in series to pin 12 of the U5 chip.

[0007] Preferably, the switching module integrates transistor Q7 and transistor Q9, with pin 2 of transistor Q7 grounded and pin 2 of transistor Q9 grounded; The third pin of transistor Q7 and the third pin of transistor Q9 are connected in parallel to the tenth pin of U5 chip. The first and third pins of transistor Q9 are electrically connected and connected in series with capacitor C11. The first pin of the transistor Q9 is electrically connected to the 5V voltage input and is connected in series with a resistor R40. The first pin of the transistor Q9 is also electrically connected to a resistor R45.

[0008] Preferably, the current detection module integrates a sampling resistor RS1, a resistor R33, and a resistor R35. The resistor R33 is electrically connected to pin 1 of the transistor Q7. The sampling resistor RS1 is connected in series with the resistor R33. The resistor R35 is connected in parallel with pin 1 of the transistor Q7. The resistor R35 is electrically connected to the 5V voltage input.

[0009] Preferably, the alarm module integrates a light-emitting diode LD1. Pins 1 and 2 of the light-emitting diode LD1 are connected to ground in parallel. Pin 3 of the light-emitting diode LD1 is connected in series with a resistor R41. Pin 3 of the light-emitting diode LD1 is electrically connected to pin 19 of the chip U5. Pin 4 of the light-emitting diode LD1 is connected in series with a resistor R37. Pin 4 of the light-emitting diode LD1 is electrically connected to pin 18 of the chip U5.

[0010] Preferably, the power module is electrically connected to an external power supply. The power module integrates a chip U1 and a transistor Q4. Pin 1 of the chip U1 is grounded. A capacitor C1 is connected in series between pin 2 and pin 1 of the chip U1. A capacitor C2 is connected in series between pin 3 and pin 1 of the chip U1. Pin 3 of the chip U1 is electrically connected to a 5V voltage input. The transistor Q4 has pins 1 and 2 connected in parallel, pin 1 of the transistor Q4 is connected in series with resistor R9, pin 2 of the transistor Q4 is connected in series with resistor R17, and pin 3 of the transistor Q4 is connected in series with resistor R8.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention proposes a current detection and protection system based on the switching characteristics of a transistor. By utilizing the switching characteristics of the transistor, current detection can be achieved without additional amplifiers or ADCs. The system has a fast response speed, which improves the efficiency of current monitoring. Protection actions can be completed in microseconds. It is low in cost, has a simple circuit design, and is easy to apply in low-power devices. The protection threshold can be flexibly adjusted, which improves the applicability of the system. Attached Figure Description

[0012] Figure 1 This utility model presents a structural block diagram of a current detection and protection system based on the switching characteristics of a transistor. Figure 2 This is the circuit diagram of the main control module in this utility model; Figure 3 This is a circuit diagram of the switching module and the current detection module in this utility model; Figure 4 This is the circuit diagram of the power module in this utility model; Figure 5 This is the circuit diagram of the alarm module in this utility model. Detailed Implementation

[0013] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0014] Reference Figure 1 As shown in the figure, a current detection and protection system based on the switching characteristics of a transistor in this embodiment of the present invention includes a main control module, a switch module, a current detection module, an alarm module and a power supply module. The input terminal of the main control module is electrically connected to the output terminal of the current detection module, the input terminal of the current detection module is electrically connected to the switch module, and the power supply module is electrically connected to the main control module for supplying power. The current detection module is used to detect current signals and transmit them to the main control module; The alarm module is electrically connected to the output of the main control module and is used to issue an alarm signal when current is detected.

[0015] like Figure 2 As shown, the main control module integrates a U5 chip. Pin 9 of the U5 chip is electrically connected to the 5V voltage input. A capacitor C9 is connected in parallel to pin 9 of the U5 chip and grounded. Pin 7 of the U5 chip is grounded. A resistor R29 is connected in series with pin 12 of the U5 chip.

[0016] The switching module integrates transistors Q7 and Q9. Pin 2 of transistor Q7 is grounded, and pin 2 of transistor Q9 is also grounded. The third pin of transistor Q7 and the third pin of transistor Q9 are connected in parallel to the tenth pin of U5 chip. The first and third pins of transistor Q9 are electrically connected and connected in series with capacitor C11. Pin 1 of transistor Q9 is electrically connected to the 5V voltage input and is connected in series with resistor R40. Pin 1 of transistor Q9 is also electrically connected to resistor R45.

[0017] The current detection module integrates sampling resistor RS1, resistor R33 and resistor R35. Resistor R33 is electrically connected to pin 1 of transistor Q7. Resistor R33 is connected in series with sampling resistor RS1. Resistor R35 is connected in parallel with pin 1 of transistor Q7. Resistor R35 is electrically connected to the 5V voltage input.

[0018] The alarm module integrates an LED LD1. Pins 1 and 2 of LED LD1 are connected to ground in parallel. Pin 3 of LED LD1 is connected in series with a resistor R41. Pin 3 of LED LD1 is electrically connected to pin 19 of chip U5. Pin 4 of LED LD1 is connected in series with a resistor R37. Pin 4 of LED LD1 is electrically connected to pin 18 of chip U5.

[0019] The power module is electrically connected to an external power supply. The power module integrates a chip U1 and a transistor Q4. Pin 1 of chip U1 is grounded. Pin 2 of chip U1 is connected in series with pin 1, and a capacitor C1 is connected in series with pin 1. Pin 3 of chip U1 is connected in series with pin 1, and a capacitor C2 is connected in series with pin 1. Pin 3 of chip U1 is electrically connected to a 5V voltage input. The first and second pins of transistor Q4 are connected in parallel. A resistor R9 is connected in series with the first pin of transistor Q4. A resistor R17 is connected in series with the second pin of transistor Q4. A resistor R8 is connected in series with the third pin of transistor Q4.

[0020] It should be noted that in this embodiment, the resistance of the sampling resistor is 5mΩ~5Ω. The transistor switching module includes at least one transistor, whose emitter is grounded, its base is connected to the circuit where the sampling resistor is located, and its collector is connected to the relevant pin of the microcontroller. The main control module detects the load current by detecting the change in the collector voltage. The U2 chip is specifically an MC51F003 chip.

[0021] like Figure 3As shown, resistors R35 and R33, along with sampling resistor RS1, constitute the current detection module. The PIN I / O pin connected to the main control module is initialized to input and its pull-up resistor is enabled. The external interrupt settings are changed to trigger an interrupt when a falling edge of the detected voltage signal is detected. The base forward voltage of the transistor is 0.7V. When no current flows through the sampling resistor, the voltage divider circuit formed by resistors R33 and R35 provides a base voltage of 0.238V. When a current of at least 9.24A flows through the sampling resistor, i.e., when the base voltage is greater than 0.7V, the collector voltage changes. In the amplification region, the relationship between the base and collector of the NPN transistor is that the larger the base voltage, the smaller the collector voltage, exhibiting a falling edge trend. The main control module will detect this trend and activate the circuit's protection mechanism.

[0022] like Figure 4 As shown, when this circuit is connected to an external power supply, the LDO in the circuit converts it to 5V and supplies power to the main control module. The transistor Q4 below acts as a circuit switch; when the corresponding pin of the main control module receives a high level input, this transistor conducts, turning on the MOSFET BSS84K above, allowing the external voltage to flow into the LDO to provide 5V to the main control module. When the circuit protection mechanism is activated, the main control module outputs a low level to shut down the power supply circuit, thus achieving the circuit protection effect.

[0023] like Figure 5 As shown, when the circuit is in operation, the current detection module accurately detects the magnitude of the current in the sampling resistor in real time. Once the current reaches the condition to trigger external interrupt protection, the main control module sends a signal to cause the LED to respond with an alarm.

[0024] In summary, the advantages of this utility model are as follows: by utilizing the switching characteristics of the transistor, current detection can be achieved without additional amplifiers or ADCs, the response speed is fast, the current monitoring efficiency is improved, the protection action can be completed in microseconds, the cost is low, the circuit design is simple, it is easy to apply in low-power devices, the protection threshold can be flexibly adjusted, and the applicability of the system is improved.

[0025] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A current detection and protection system based on transistor switching characteristics, characterized in that, It includes a main control module, a switch module, a current detection module, an alarm module, and a power supply module. The input terminal of the main control module is electrically connected to the output terminal of the current detection module. The input terminal of the current detection module is electrically connected to the switch module. The power supply module is electrically connected to the main control module and is used to supply power. The current detection module is used to detect current signals and transmit them to the main control module; The alarm module is electrically connected to the output terminal of the main control module and is used to issue an alarm signal when current is detected.

2. The current detection and protection system based on transistor switching characteristics according to claim 1, characterized in that, The main control module integrates a U5 chip. Pin 9 of the U5 chip is electrically connected to the 5V voltage input. A capacitor C9 is connected in parallel to pin 9 of the U5 chip and grounded. Pin 7 of the U5 chip is grounded. A resistor R29 is connected in series with pin 12 of the U5 chip.

3. The current detection and protection system based on transistor switching characteristics according to claim 2, characterized in that, The switching module integrates transistors Q7 and Q9. Pin 2 of transistor Q7 is grounded, and pin 2 of transistor Q9 is also grounded. The third pin of transistor Q7 and the third pin of transistor Q9 are connected in parallel to the tenth pin of U5 chip. The first and third pins of transistor Q9 are electrically connected and connected in series with capacitor C11. The first pin of the transistor Q9 is electrically connected to the 5V voltage input and is connected in series with a resistor R40. The first pin of the transistor Q9 is also electrically connected to a resistor R45.

4. The current detection and protection system based on transistor switching characteristics according to claim 1, characterized in that, The current detection module integrates a sampling resistor RS1, a resistor R33, and a resistor R35. The resistor R33 is electrically connected to pin 1 of the transistor Q7. The sampling resistor RS1 is connected in series with the resistor R33. The resistor R35 is connected in parallel with pin 1 of the transistor Q7. The resistor R35 is electrically connected to the 5V voltage input.

5. A current detection and protection system based on transistor switching characteristics according to claim 1, characterized in that, The alarm module integrates a light-emitting diode LD1. Pins 1 and 2 of the light-emitting diode LD1 are connected to ground in parallel. Pin 3 of the light-emitting diode LD1 is connected in series with a resistor R41. Pin 3 of the light-emitting diode LD1 is electrically connected to pin 19 of the chip U5. Pin 4 of the light-emitting diode LD1 is connected in series with a resistor R37. Pin 4 of the light-emitting diode LD1 is electrically connected to pin 18 of the chip U5.

6. A current detection and protection system based on transistor switching characteristics according to claim 1, characterized in that, The power module is electrically connected to an external power source. The power module integrates a chip U1 and a transistor Q4. Pin 1 of the chip U1 is grounded. A capacitor C1 is connected in series between pin 2 and pin 1 of the chip U1. A capacitor C2 is connected in series between pin 3 and pin 1 of the chip U1. Pin 3 of the chip U1 is electrically connected to a 5V voltage input. The transistor Q4 has pins 1 and 2 connected in parallel, pin 1 of the transistor Q4 is connected in series with resistor R9, pin 2 of the transistor Q4 is connected in series with resistor R17, and pin 3 of the transistor Q4 is connected in series with resistor R8.

Images